I have done this for work the other day. I had to take the picture of the manager separately in his office against a white background as i couldn't set my lighting up on the platform due to the overhead lines (25,000 volts) at the train station.
I then took the image of the station and then superimposed him onto the background.

This is really great. I second the idea of lowering the brightness of the background a bit. I also would clone out that top left corner (well, it distracts me from his head, but maybe I'm the only one lol). Nice concept, you did an excellent job! I am sure they will love this.

Nice lighting on the manager and I like the juxtaposition of his static image with the movement in the background. Not that it's an issue for me, but it does scream composite. Is the choice of lens different on the two shots?